Information processing apparatus and information processing method

ABSTRACT

While presenting on a display apparatus videos of high picture quality obtained from portable video processing apparatuses such as a camera and a cellular, it is possible to communicate with the Internet and/or a home network. A display apparatus includes a first radio communication unit capable of receiving video information by radio from an external video processing apparatus, a second radio communication unit capable of connecting by radio to a network, and a control unit for controlling assignment of connection by radio transmission for each of the first and second radio communication units. The control unit assigns connection of the first radio communication unit with higher priority and controls the assignment of the transmission rate such that the transmission rate between the first radio communication unit and the external video processing apparatus is more than that between the second radio communication unit and the network.

INCORPORATION BY REFERENCE

The present application is a continuation of U.S. patent applicationSer. No. 16/738,059, filed Jan. 9, 2020 which is a continuation of U.S.patent application Ser. No. 16/269,662, filed Feb. 7, 2019, (now U.S.Pat. No. 11,451,860), which is a continuation of U.S. patent applicationSer. No. 15/891,085, filed on Feb. 7, 2018, (now, U.S. Pat. No.10,244,284), which is a continuation of U.S. patent application Ser. No.15/208,886, filed on Jul. 13, 2016 (now, U.S. Pat. No. 10,129,590),which is a continuation of U.S. patent application Ser. No. 12/260,410,filed on Oct. 29, 2008 (now, U.S. Pat. No. 9,420,212), which claimspriority to Japanese Patent Application No. 2007-306750, filed on Nov.28, 2007, the contents of all of which are hereby incorporated byreference into this application.

BACKGROUND OF THE INVENTION

The present invention relates to a technique to establish connectionsbetween a plurality of apparatuses and networks by radio.

To connect a video processing apparatus to a video display apparatus asanother video processing apparatus to view videos, there has beenemployed a method to establish analog connections therebetween totransmit video and audio signals. However, as digital apparatuses havebeen widely spread, there is employed, to prevent picture qualitydeterioration and to protect copyright of contents to be viewed, amethod in which digital connections are established between theapparatuses and video and audio signals are encrypted to be transmittedtherebetween.

High Definition Digital Multimedia Interface (HDMI) is known as anexample of an interface for digital transmission. According to the HDMI,the base band signal and the audio signal of high definition aretime-division multiplexed and the resultant signal is encrypted throughHDCP for transmission thereof.

A conventional technique in which digitized video and audio signals aremultiplexed for transmission as above is described in, for example,JP-A-2007-202115.

SUMMARY OF THE INVENTION

According to the HDMI, which is developed on assumption of uses forconnections between apparatuses installed in a house of a family,consideration has not been given to connections with the internet and anetwork in the family or a home network while viewing high-qualityvideos. It is therefore an object of the present invention, devised toovercome the difficulty, to provide a technique wherein while presentingon a display apparatus videos of high picture quality obtained fromportable video processing apparatuses such as a camera and a cellularphone, it is possible to communicate with the internet and/or a homenetwork.

According to one aspect of the resent invention, there is provided adisplay apparatus including a first radio communication unit capable ofreceiving video information by radio from an external video processingapparatus, a second radio communication unit capable of connecting byradio to a network, and a connection assignment control unit forcontrolling assignment of connection by radio transmission for each ofthe first and second radio communication units. The control unit assignsconnection of the first radio communication unit with higher priorityand controls the assignment of the transmission rate, for example, suchthat the transmission rate between the first radio communication unitand the external video processing apparatus is more than thetransmission rate between the second radio communication unit and thenetwork.

According to another aspect of the present invention, there is provideda video processing apparatus including a first radio communication unitcapable of transmitting video information by radio to an externaldisplay apparatus, a second radio communication unit capable ofconnecting by radio to a network, and a connection assignment controlunit for controlling assignment of connection by radio transmission foreach of the first and second radio communication units. The control unitassigns connection of the first radio communication unit with higherpriority and controls the assignment of the transmission rate, forexample, such that the transmission rate between the first radiocommunication unit and the external video display apparatus is more thanthe transmission rate between the second radio communication unit andthe network.

In the display apparatus constructed as above, the first radiocommunication unit can communicate video information of high picturequality with an external video processing apparatus. The second radiocommunication unit can connect by radio to the internet and a homenetwork. The controller controls the transmission rate of the radiotransmitter module to be assigned to the first radio communication unitand can change the transmission rate of the radio transmitter module tobe assigned to the second radio communication unit. It is possible forthe controller to determine and to control the radio transmission ratesto be assigned to the first and second radio communication units. Thecontroller controls the operation such that the assignment to the firstradio communication module to conduct transmission to receive videoinformation from an external video processing apparatus is carried outwith higher priority. Therefore, it is possible that video informationof high picture quality is continuously fed from the video processingapparatus to the video information apparatus as well as information istransmitted from the internet and a home network. There can be henceprovided a video display apparatus having high serviceability.

According to the present invention, it is possible to communicate with anetwork while displaying videos of high picture quality obtained by avideo processing apparatus.

Other objects, features and advantages of the invention will becomeapparent from the following description of the embodiments of theinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an example of an embodiment of a videoprocessing apparatus 100 according to the present invention;

FIG. 2 is a block diagram showing an example of an embodiment of a videodisplay apparatus 200 according to the present invention;

FIG. 3 is a block diagram showing another example of an embodiment of avideo display apparatus 200 according to the present invention;

FIG. 4 is a diagram showing an example of a radio modulator anddemodulator or modem of the video processing apparatus 100;

FIG. 5 is a block diagram showing an example of a system in which twovideo processing apparatuses are wirelessly connected to each other;

FIG. 6 is a block diagram showing another example of a system in whichtwo video processing apparatuses are wirelessly connected to each other;

FIG. 7 is a diagram showing an example of structure of the HDMI;

FIG. 8 is a diagram showing an example of a radio modem of the videodisplay apparatus;

FIG. 9 shows a diagram showing an example of transmission parameters ofa radio modem in the embodiment;

FIG. 10 is a diagram showing connections between the video processingapparatus 100 and the video display apparatus 200 in the embodiment ofthe present invention; and

FIG. 11 is a diagram showing an example of assignment of bands inanother example of a radio modem shown in FIGS. 4 and 8 .

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring now to the drawings, description will be given of anembodiment according to the present invention.

First Embodiment

FIG. 10 shows an embodiment of the present invention. In this example,the system includes two video processing apparatuses, i.e., a videoprocessing apparatus 100 which is, for example, a portable videoprocessing apparatus capable of receiving a digital broadcast signal viaa base station antenna for cellular phones or a broadcast transmissiontower and a video display apparatus 200 such as a tuner capable ofreceiving a digital broadcast signal from a broadcast transmissiontower. These apparatuses are connected, for example, via a bidirectionalinterface 10 to each other. Resultantly, a video signal of high picturequality and other information items and signals can be bidirectionallycommunicated therebetween. On the other hand, between a terminal 134 ofthe video processing apparatus 100 and a terminal 202 of the videodisplay apparatus 200, signals from the internet and a home network arecommunicated by radio. The frequency bands used for the transmissionbetween the terminals 134 and 202 are limited to predetermined frequencybands. This increases the radio wave resource efficiency and preventsthe problem of interference with other apparatuses.

In the embodiment, the portable video processing apparatus 100 isspecifically, for example, a digital camera, a video camera, a cellularphone, a game machine, or a personal media player.

FIG. 1 shows a concrete example of the video processing apparatus 100employed in the first embodiment of the present invention. This is aspecific configuration of the apparatus 100 shown in FIG. 10 . In FIG. 1, an imaging device 110 receives a moving or still picture supplied viaan optical system to convert the picture into en electric signal. Totransmit a moving picture, a compression circuit 111 employs acompression method, e.g., Moving Picture Experts Group 2 (MPEG2), MPEG4,or AVC/H.264. To transmit a still picture, the compression circuit 111employs a compression method, e.g., Joint Photographic Experts Group(JPEG). The compression circuit 111 efficiently bit-compresses thereceived image.

A microphone 112 converts sound into an electric signal. A compressioncircuit 113 uses a compression method such as an MPEG audio toefficiently bit-compress the received audio signal.

A multiplexer circuit 116 receives the bit-compressed video and audiosignals from the compression circuits 111 and 113 and variousinformation items from a microprocessor 115. By use of the informationitems, the multiplexer 116 multiplexes the signals according to apredetermined format. When a still picture is shot, the audio signal isnot obtained in an ordinary case. However, it is also possible tomultiplex an audio signal in synchronism with the still picture shootingoperation.

The information items from the microprocessor 115 include, for example,positional information (horizontal positions, vertical positions on theright, and vertical positions on the left), date, and exposureinformation at shooting.

In FIG. 1 , the multiplexed signal from the multiplexer 116 is fed viaan encryption/decryption circuit 140 to be stored in a storage 130. Thestorage 130 may be, for example, a hard disk device, an optical diskdevice, or a semiconductor memory device. The type of the storage 130may be determined according to, for example, a storage capacity, a sizeof the storage 130, easiness of removing a storage medium, and/or aprice of the storage 130 according to necessity. It is also possible tostore the multiplexed signal via a signal processing circuit 124 and amemory interface 120 in a memory 121.

When information is shot by a particular person, copyright of theinformation belongs to the person. Hence, ordinarily, such informationis not required to be encrypted for the storage thereof. However, thestorage medium having stored information by the storage 130 may be lost.It will be more safe if the multiplexed signal from the multiplexer 116is once encrypted by the encryption/decryption circuit 140 to be storedin the storage 130 or the memory 121.

The video processing apparatus 100 may also support the use of aremovable memory or include a cellular phone function or a radio LocalArea Network (LAN) function. The memory interface 120 is an interfacefor a removable memory 121. When video and audio contents of still andmoving pictures are recorded by another apparatus in the memory 121 andthe memory 121 is connected to the interface 120, the contents can berecorded via the signal processing circuit 124 and theencryption/decryption circuit 140 into the storage 130.

In this situation, the signal processing circuit 124 checks to determinewhether or not the copyright of the contents recorded in the memory 121is protected and whether or not the duplication thereof is prohibited.According to the detected condition, the encryption/decryption circuit140 encrypts the contents and moves the encrypted contents in thestorage 130.

Similarly, audio and video contents of still and moving pictures arereceived as inputs by a radio interface 122. The contents are stored viathe signal processing circuit 124 and the encryption/decryption circuit140 in the storage 130. Also, according to conditions of the copyrightprotection and the replication restriction, the contents are encryptedby the encryption/decryption circuit 140, as required.

When it is desired to reproduce a content stored in the storage 130 toview the reproduced content, the user selects the content by an inputkey or a remote control, not shown. The selected content is read fromthe storage 130 to be decoded by the encryption/decryption circuit 140and is then separated by a demultiplexer circuit 141 into an audiosignal and a video signal.

When a broadcast program is received by a broadcast receiver 180, theencrypted signal encrypted for the broadcast is decrypted by theencryption/decryption circuit 140. If encryption is required to storethe signal, the signal is accordingly encrypted by the circuit 140 to bestored in the storage 130 and the memory 121. To immediately view thereceived broadcast program in real time, the signal is separated by thedemultiplexer 141 into a video signal and an audio signal.

The separated and compressed video signal is decompressed by adecompression circuit 142 to be fed to a signal processing circuit 150.The circuit 150 conducts a scanning-line conversion for the video signalon the basis of the number of scanning lines of a display 160 to outputthe resultant video signal to the display 160. The separated andcompressed audio signal is decompressed by a decompression circuit 143to be delivered to an audio output device 161. Since the videoprocessing apparatus 100 includes the display 160 and the audio outputdevice 161, it is possible to immediately view the broadcast programwithout externally connecting any video display apparatus. In asituation wherein the period of time required for the decompressionvaries between the video and audio signals and/or a time differenceexists between the video display and the audio output due to presence orabsence of the scanning-line conversion, if the audio signal is advancedin time relative to the video signal, the user particularly perceives anuncomfortable feeling. To overcome the difficulty, the audio signal isdelayed, for example, in the decompression processing, namely, alip-sync operation is carried out. This removes the uncomfortablefeeling due to the difference in time between the video and audiosignals.

Description will now be given of a situation wherein the videoprocessing apparatus 100 is employed as a cellular phone. For example, avoice of a conversation is inputted to the audio input/output section126 to produce an electric signal. For the signal, a telephone signalprocessing circuit 125 executes predetermined signal processing andmodulation processing. The resultant signal is transmitted via anantenna, not shown, to a base station of the cellular phone. An audiosignal sent from the base station is received by an antenna, not shown,to be fed to the telephone signal processing circuit 125. For thesignal, the circuit 125 executes predetermined signal processing anddemodulation processing. The resultant signal is fed to the audio I/Osection 126 to be reproduced as a voice. The video processing apparatus100 can also receive a content of a moving picture transmitted from thebase station of the cellular phone. The content is received by anantenna, not shown, to be delivered via the telephone signal processingcircuit 125 to the signal processing circuit 124. The content issimilarly processed as above by the encryption/decryption circuit 140.The resultant signal of the content is fed to a display and an audiooutput unit incorporated in the video processing apparatus 100 to beviewed/listened by the user. The content thus processed may also be fedvia a terminal 101, a connection cable 10, and a terminal 201 to anexternal video display apparatus 200 to be displayed on a large-sizedscreen. While viewing the content, it is possible to record the contentin a recording medium incorporated in the video processing apparatus 100or a recording medium, e.g., a memory 121 connected thereto, forexample, to view the content later. The memory 121 may also be used as arecording medium to record a movie and the like.

Similarly, a program broadcast from a broadcast transmission tower isreceived by a broadcast receiver 180 of the video processing apparatus100 to be viewed by the apparatus 100 or to be stored in a recordingmedium, not shown, incorporated in the apparatus 100 or a recordingmedium, e.g., the memory 121 connected thereto. Also, the content may befed via the terminal 101, the cable 10, and the terminal 201 to thevideo display apparatus 200 to be viewed by the user.

In addition, by installing an imaging device 110 and a microphone 112 inthe video processing apparatus 100, still and moving pictures can beshot together with audios and can be stored in an incorporated recordingmedium, not shown, and/or the memory 121. The videos and audios storedin the recording medium and/or the memory 121 may be fed via theterminal 101 to the video display apparatus 200 to be enjoyed by theuser.

When the user views video and audio signals by use of the external videodisplay apparatus 200, the apparatus 200 confirms scanning lines whichthe apparatus 200 can support. If the scanning lines match those of thevideo signals to be displayed, the signals are immediately outputted inreal time. Otherwise, the scanning lines of the video signals areconverted by a signal processing circuit 150 into the required scanninglines to be fed to a multiplexer circuit 170. In the circuit 170, thevideo signals are multiplexed on the time axis, with the audio signalsprocessed by a signal processing circuit 151. The circuit 151 compressesthe audio signals on the time axis during a period corresponding to theblanking period of the video signals and conducts a time adjustingoperation to carry out the lip-sync operation according to thenecessity. The video and audio signals multiplexed by the multiplexercircuit 170 are delivered to an encryption circuit 171. For the signals,the circuit 171 carries out encryption for the transmission of thesignals between the video processing apparatus 100 and the video displayapparatus 200 and outputs the resultant signals via a video interfacecircuit 131, a transmission rate assignment controller 1001, and theterminal 101 to the video display apparatus 200. On the other hand, theterminal 134 is connected to a network such as the internet as describedabove and is used to wirelessly communicate videos and other informationitems obtained from the network by use of a radio modem circuit 1003.The information from the network is demodulated by the circuit 1003 tobe fed via the transmission rate assignment controller 1001 to aninterface circuit 133 and is delivered therefrom to a microprocessor115. The microprocessor 115 determines the type of the information fromthe network. If the information is, for example, a video streamcompressed in a predetermined format, the microprocessor 115 feeds thevideo stream to the demultiplexer circuit 141 and the decompressioncircuit 143. For the video stream, the circuits 141 and 143 conductprocessing as described above. The resultant signals are presented onthe display 160. According to necessity, the audio information obtainedfrom the network is reproduced by the audio output device 161. If theinformation from the network is an update program of an applicationprogram or an Operating System (OS), the microprocessor 115 executesaddition and storage processing for new software or executes updateprocessing for the associated program. Although the processing of thenetwork information is executed by the microprocessor 115 to processvideo information in the embodiment, it is also possible to arrange amicroprocessor to dedicatedly process the network information.

The controller 132 controls the transmission rate assignment controlcircuit 1001 on the basis of time control information of the videosignal to variably control the transmission rate of the radio modemcircuit 1002. At the same time, the controller 132 variably controls thetransmission rate of the radio modem circuit 1003 for radiocommunication with a network such as the Internet. According to theembodiment, in the assignment of the transmission rate to thedemodulation circuits 1002 and 1003, the controller 132 gives preferenceto the demodulation circuit 1002. In other words, the transmission rateof the demodulation circuit 1002 is more than that of the modem circuit1003. Hence, within the limited range of bands for the radiotransmission, the modem 1002 can transmit video information withoutdeteriorating the video quality of the video information having highpicture quality. The band of radio signals from the terminal 101 andthat of radio signals from the terminal 134 are fixed. Therefore, if theband of signals from the terminal 101 is expanded, that of signals fromthe terminal 134 narrows to slightly lower the communication speed ofthe network. However, this rarely influences the system operation sinceinformation regarding the network is less frequently exchanged ascompared with video information sent from the video processing apparatus100.

When the signal from the terminal 101 is to be stored in the destinationthereof, the compressed signal is transmitted without decompressing thesignal. In the operation, the encryption/decryption circuit 140 deliversthe compressed signal to the encryption circuit 171. The circuit 171conducts predetermined encryption for the signal and then outputs theresultant signal via the video interface circuit 131, the transmissionrate assignment controller 1001, and the terminal 101. Also in thissituation, the control circuit 132 variably controls the transmissionrate of the radio modem 1002 in association with the time controlinformation of the video signal. As a result, the radio modem 1002 cansend the video information without deteriorating the video quality ofthe video information having high picture quality.

In the description above, the video and audio signals obtained from theimaging device 110 and the microphone 112 and the contents inputted fromthe memory 121 and the radio interface 122 are once stored in thestorage 130 to be thereafter reproduced. However, if the storing of thesignals and the contents are not required or are immediately viewed, thesignals and the contents are demultiplexed by the demultiplexer 141without conducting the encryption and decryption for the storage by theencryption/decryption circuit 140. Resultantly, the videos and audioscan be enjoyed by use of the display 160 and the audio output device 161of the video processing apparatus 100. Also, it is possible to enjoy thevideos and audios by a receiver externally connected via the wiredinterface circuit 131 to the apparatus 100.

Description will now be specifically given of one technical aspect ofthe embodiment, namely, the transmission rate assignment control circuit1001 and the radio demodulation circuits 1002 and 1003. The modemcircuits 1002 and 1003 conduct demodulation through Orthogonal FrequencyDivision Multiplexing (OFDM). In the example, the modem 1002 is a firstradio communication unit which wirelessly sends video information andaudio information to the external video display apparatus 200 and whichreceives data and information by radio therefrom. The modem 1002 isconnected via the transmission rate assignment controller 1001 to theinterface circuit 131 which communicates with the video displayapparatus 200. On the other hand, the modem 1003 is a second radiocommunication unit which connects to (accesses) a network, e.g., theInternet or a home network to wirelessly communicate various informationincluding video signals, audio signals, and data therewith. The modem1003 is connected via the transmission rate assignment controller 1001to the interface circuit 133 for networks. The controller 1001 variablycontrols, according to a control signal from the controller 132, thetransmission rates respectively of the modems 1002 and 1003 by variablysetting the modulation/demodulation methods, the frequency bands, andthe number of carriers respectively for the modems 1002 and 1003. Inshort, the controller 132 controls distribution of the radiotransmission rate of each modem by controlling the transmission rateassignment controller 1001. As a specific example of operation in whichthe transmission rate is controlled by changing parameters including thedemodulation method and the frequency band, FIG. 9 shows the differencein the transmission rate between two schemes.

According to the embodiment, the controller 132 and the transmissionrate assignment controller 1001 control the radio transmissionassignment such that the radio transmission rate of the modem 1002 tosend the video information of high picture quality by radio to the videodisplay apparatus 200 takes precedence over the radio transmission rateof the modem 1003 to connect to a network for communication. That is,the radio transmission rate of the modem 1002 is more than that of themodem 1003. For example, in a situation wherein the modem 1002 transmitsvideo information to the display apparatus 200 and the modem 1003simultaneously connects to the Internet to receive Internet information,the controller 132 controls the operation to continuously supply videoswith high picture quality to the user, specifically, to set thetransmission scheme of the modem 1002 to, for example, “scheme 1” shownin FIG. 9 . For the radio modem 1003, the controller 132 sets thetransmission scheme thereof to “scheme 2” of FIG. 9 . As can be seenfrom FIG. 9 , the transmission capacity of scheme 1 is 17 Megabits persecond (Mbps) which is more than three times that of scheme 2 (5 Mbps).As above, in the limited transmission capacity for radio transmission, ahigher transmission rate is assigned to the communication with thedisplay apparatus 200 in the embodiment. It is hence possible that theuser continuously views videos with high picture quality on the displayapparatus 100. Naturally, the variable control of the transmission rateis not limited to the example shown in FIG. 9 .

The controller 132 and the transmission rate assignment controller 1001may variably control the radio transmission assignment to the modems1002 and 1003 in response to an indication from the user. For example,in a situation wherein the user issues an indication to transmit videoinformation by radio via the modem 1002 to the display apparatus 200while acquiring information from the Internet according to scheme 1 ofFIG. 9 by use of the modem 1003, the controller 132 outputs a controlsignal to the assignment controller 1001 such that the transmissionscheme of the modem 1003 is changed from scheme 1 to scheme 2 of FIG. 9and that of the modem 1002 is set to scheme 1 of FIG. 9 conductcommunications. The transmission rate of the modem 1002 may be variablychanged according to fineness or precision of the video information sentfrom the modem 1002 to the display apparatus 200. For example, if thefineness of the video information is altered from SD (640×480) to HD(1980×1080), the controller 132 instructs the assignment controller 1001to heighten the transmission rate of the modem circuit 1002. It ispreferable in the operation that the transmission rate of the modem 1003is lowered in association with the variable control of the transmissionrate of the modem 1002.

The transmission rates of the radio modems 1002 and 1003 may also bevariably controlled by a communication technique using a plurality ofantennas such as a Multi-Input Multi-Output (MIMO) scheme.

Referring next to FIG. 4 , description will be given of other examplesof the transmission rate assignment controller and the radio modem. FIG.4 shows only part of the system associated with the transmission rateassignment control. In FIG. 4 , the same functional constituentcomponents as those of FIG. 1 are assigned with the same referencenumerals.

In FIG. 4 , radio modem circuits 5001 to 5004 are modems havingrespective fixed transmission capacity values and differ from each otheronly in the frequency band for transmission. The modems 5001 to 5004respectively have bands A to D as shown in FIG. 11 . Terminals 101 and5005 to 5007 are input terminals to receive signals and are arrangedrespectively for radio modems 5001 to 5004. In operation, the modems5001 to 5004 may be appropriately combined with each other. For example,according to necessity, the modems 5001 and 5002 are employed totransmit video information and the modems 5003 and 5004 are utilized tocommunicate with the network such as the Internet. That is, while theinterface circuit 131 wirelessly transmits video information and audioinformation via the modems 5001 and 5002 to the video display apparatus200, the interface circuit 133 conducts communication via the modems5003 and 5004 with the network. In a situation wherein a wide band isrequired to transmit video information of high picture quality (e.g.,video information of HD resolution), the modems 5001 to 5003 areassigned to send video information and only the modem 5004 is assignedto communicate with the network such as the Internet. Specifically, theinterface circuit 131 transmits video and audio information by radio viathe modems 5001 to 5003 to the display apparatus 200, and the interfacecircuit 133 communicates with the network via the modem 5004. As aresult, video information of high picture quality can be continuouslytransmitted and it is also possible to communicate with the Internet.Particularly, the broadcast signal is required to be presented bysynchronizing the time information sent from the broadcasting stationwith that on the receiver side. According to the present invention, thetime information can be appropriately controlled without deterioratingthe quality of the video information.

FIG. 2 shows a specific configuration of the video display apparatus 200of FIG. 10 . In FIGS. 2 and 10 , the same constituent components areassigned with the same reference numerals and detailed descriptionthereof will be avoided. Description will be given of a situationwherein an uncompressed baseband signal of a moving picture is inputtedvia the terminal 201. The signal from the external video processingapparatus 100 thus received via the terminal 201 is demodulated by aradio modem circuit 2015 to be supplied via a transmission rateassignment controller 2017 and an input/output interface circuit 2011 toa decryption circuit 211. In operation, a controller 2013 drives theassignment controller 2017 to vary the transmission rate of the modem2015 according to that of the video information delivered from the videoprocessing apparatus 100. Resultantly, an input/output interface circuit2011 can receive the video information of high picture quality at presettiming.

The decryption circuit 211 is associated with encryption by theencryption circuit 171 shown in FIG. 1 and decrypts a signal encryptedby the circuit 171. The decrypted signal is fed to a demultiplexercircuit 250, and then video and audio signals obtained from thedemultiplexer 250 are inputted to signal processing circuits 251 and252, respectively. For the received video signal, the circuit 251conducts a scanning-line conversion and a resolution conversionaccording to the number of pixels displayable by a display 260. Thecircuit 252 decompresses on the time axis the audio signal which iscompressed and multiplexed on the time axis by use of the blanking ofthe video signal. According to necessity, the circuit 252 carries outthe lip-sync operation and the sound quality adjustment. Signalsoutputted respectively from the circuits 251 and 252 are inputtedrespectively to a display 260 and an audio input/output unit 270 to beviewed by the user.

Description will now be given of operation when a compressedmoving-picture signal is received via the terminal 201. This operationaims at storing the moving-picture signal in a storage 230 incorporatedin the apparatus 200.

The signal received from the terminal 201 is delivered via the wiredinput/output interface circuit 2011 to the decryption circuit 211. Thecircuit 211 corresponds to the encryption circuit 171 shown in FIG. 2and decrypts a signal encrypted by the circuit 171. The decrypted signalis inputted to an encryption/decryption circuit 240. The circuit 240reads copy control information of the content to be stored and encryptsthe content for the storage thereof according to the information. Theencrypted signal is stored in the storage 230 in the compressed state.

In a situation wherein the user views the compressed signal received viathe terminal 201 while storing the signal in the storage, a signalcorresponding to a compressed signal decrypted by theencryption/decryption circuit 211 is fed from the encryption/decryptioncircuit 240 to a demultiplexer circuit 241. In the circuit 241, thesignal is separated into a compressed video signal and a compressedaudio signal. The separated video and audio signals are decompressedrespectively by decompression circuits 242 and 243 to baseband signalsto be respectively supplied to the signal processing circuits 251 and252. Signals outputted respectively therefrom are delivered respectivelyto the display and the audio output unit 270 to be viewed by the user.

When a content stored in the storage 230 is reproduced to be viewed bythe user, information items such as titles of the contents stored in thestorage 230 are presented on the display 260. When the user selects oneof the contents, a signal of the selected content is fed from thestorage 230 to the encryption/decryption circuit 240. The circuit 240decrypts the encrypted signal of the content to input the resultantsignal to the demultiplexer 241. The signal of the content is thereaftersimilarly processed as described above to be viewed by the user.

It is possible to similarly reproduce contents stored in a memory 221.As in the reproduction of contents stored in the storage 230, the userselects one of the contents stored in a memory 221 to view the content.The selected content is transferred via a memory interface 220 and asignal processing circuit 224 to the encryption/decryption circuit 240.Specifically, the circuit 224 executes processing necessary to read thecontent from the memory 221 to input compressed and multiplexed videoand audio signals of the content to the circuit 240. Subsequent signalprocessing is similar to the processing executed after the content isread from the storage 230.

As in the operation to store a content in the storage 230, it ispossible to store the content in the memory 221. Although detaileddescription of the associated processing will be avoided, the contentencrypted by the encryption/decryption circuit 240 is stored via thesignal processing circuit 224 and the memory interface 220 into thememory 221.

To view or to store a content transmitted by radio, the system executesprocessing in a similar way. A compressed content received by radio isfed via a radio interface 222 and the signal processing circuit 224 tothe encryption/decryption circuit 240. The circuit 240 decrypts thesignal encrypted for the radio transmission. Subsequent processing issimilar to the processing executed at reproduction of the signal fromthe storage 230.

When an uncompressed baseband signal is received from the terminal 201or 202, the content can be efficiently stored in the storage 230 and thememory 221. Description will be given of operation in this situation.

The content inputted from the terminal 201 is transferred via theinput/output interface 2011, the decryption circuit 211 and thedemultiplexer circuit 250 to be separated into a video signal and anaudio signal. The video and audio signals thus separated are fed via areplication control circuit 280 to compression circuits 281 and 282. Thecircuit 280 reads, from the content, multiplexed replication controlinformation to determine whether or not replication of the content isallowed. As the control information, a bit may be assigned to adesignated field. Or, by using electronic watermark, the information maybe superimposed onto video or audio information. Information inputtedfrom the network to the terminal 202 is also processed in a similarfashion as above.

The compression circuit 281 compresses the video signal by use of acompression scheme, e.g., MPEG2, MPEG4, or AVC/H.264. The compressioncircuit 282 compresses the audio signal according to a compressionscheme, e.g., MPEG Audio. The compressed video and audio signals areinputted to a multiplexer circuit 283 to be multiplexed. The multiplexedsignal is fed to the encryption/decryption circuit 240 to be thereaftersimilarly stored in the storage 230 and/or the memory 221. As a result,the content can be efficiently recorded therein for a long period oftime according to copyright information.

On the other hand, the signal from a network such as the Internetreceived via the terminal 202 is demodulated by a radio modem circuit2016 to be supplied via a transmission rate assignment controllercircuit 2017 and an input/output interface circuit 2012 to amicroprocessor 279. The type of information of the video informationfrom the network is determined. If the information is, for example, avideo stream compressed in a predetermined format, the system transfersthe information to demultiplexer circuit 241 and the decompressioncircuits 242 and 243. After the information is processed by thesecircuits in a similar way as described above, an image of theinformation is presented on the display 260. According to necessity,audio information obtained from the network is reproduced by the audiooutput unit 261. If the information from the network is an updateprogram for an application program, an operating system OS, or the like,the microprocessor 279 adds and stores new software and/or updates anassociated program. It is also possible that the function of themicroprocessor 279 is installed in the controller 2013 to configure oneunified module including the microprocessor 279 and the controller 2013.

In the operation, the controller 2013 controls the transmission rateassignment controller 2017 to vary the transmission rate of the radiomodem 2015 in association with the transmission rate of the videoinformation received from the video processing apparatus 100. Since thetransmission rate of the radio modem 2015 to receive the videoinformation from the apparatus 100 takes precedence over that of themodem 2016 in the transmission rate assignment, the transmission rate ofthe modem 2016 is lower than that of the modem 2015. In the embodimentas described above, the transmission rate of the modem 2015 to receivethe video information from the apparatus 100 is higher than that of themodem 2016 to communicate with the network. Therefore, within thelimited range of bands for the radio transmission, it is possible toobtain the high-quality video information from the external videoprocessing apparatus 100 without deteriorating the video quality. Theband of radio signals received by the terminal 201 and that of radiosignals inputted to the terminal 202 are fixed. Hence, if the band ofsignals from the terminal 201 is expanded, that of signals from theterminal 202 narrows. This slightly lowers the communication speed ofthe network. However, this rarely influences the system operation sinceinformation regarding the network is less frequently exchanged ascompared with video information sent from the video processing apparatus100.

Next, description will be specifically given of one technical aspect ofthe embodiment, namely, the transmission rate assignment controller 2017and the radio modems 2015 and 2016. The modems 2015 and 2016 carry outOFDM modulation/demodulation. In the example, the modem 2015 is a firstradio communication unit which wirelessly receives video information andaudio information from the external video processing apparatus 100 andwhich sends data and information by radio to the apparatus 100. Themodem 2015 is connected via the transmission rate assignment controller2017 to the interface circuit 2011 which communicates with the videodisplay apparatus 200. On the other hand, the modem 2016 is a secondradio communication unit which connects to (accesses) a network, e.g.,the Internet or a home network to wirelessly communicate variousinformation including video signals, audio signals, and data with thenetwork. The modem 2016 is connected via the transmission rateassignment controller 2017 to the interface circuit 2012 for networks.The controller 2017 variably controls, according to a control signalfrom the controller 2013, the transmission rates respectively of themodems 2015 and 2016 by variably designating the modulation/demodulationmethods, the frequency bands, and the number of carriers respectivelyfor the modems 2015 and 2016. In other words, the controller 2013controls distribution of the radio transmission rate of each modem bycontrolling the transmission rate assignment controller 2017. As aspecific example of operation in which the transmission rate iscontrolled by changing parameters including the demodulation method andthe frequency band, FIG. 9 shows the difference in the transmission ratebetween two schemes.

In the embodiment, the controller 2013 and the transmission rateassignment controller 2017 control the radio transmission rateassignment so that the radio transmission rate of the modem 2015 toreceive the video information of high picture quality by radio from theexternal video processing apparatus 100 takes precedence over the radiotransmission rate of the modem 2016 to connect to a network forcommunication. In short, the radio transmission rate of the modem 2015is more than that of the modem 2016. For example, in a situation whereinthe modem 2015 receives video information from the video processingapparatus 100 and the modem 2016 simultaneously connects to the Internetto receive Internet information, the controller 2013 controls theoperation to continuously provide videos with high picture quality tothe user, specifically, to set the transmission scheme of the modem 2015to, for example, “scheme 1” shown in FIG. 9 . For the radio modem 2016,the controller 2013 sets the transmission scheme thereof to “scheme 2”shown in FIG. 9 . As can be seen from FIG. 9 , the transmission capacityof scheme 1 is 17 Mbps which is more than three times that of scheme 2(5 Mbps). Hence, in the limited transmission capacity for radiotransmission, a higher transmission rate is assigned to thecommunication with the video processing apparatus 100 in the embodiment.It is therefore possible that the user continuously watches videos withhigh picture quality on the display apparatus 100. Naturally, thevariable control of the transmission rate is not limited to the exampleshown in FIG. 9 .

The controller 2013 and the transmission rate assignment controller 2017may control the radio transmission assignment to the modems 2015 and2016 in response to an indication from the user. For example, in asituation wherein the user issues an indication to receive videoinformation by radio via the modem 2015 from the video processingapparatus 100 while acquiring information from the Internet according toscheme 1 of FIG. 9 by use of the modem 2016, the controller 2013 outputsa control signal to the assignment controller 2017 such that thetransmission scheme of the modem 2016 is changed from scheme 1 to scheme2 of FIG. 9 and that of the modem 2015 is set to scheme 1 of FIG. 9 .The transmission rate of the modem 2015 may be changed according toprecision of the video information which is sent from the videoprocessing apparatus 100 to be received by the modem 2015. For example,the precision of the video information above is changed from SD(640×480) to HD (1980×1080), the controller 2013 instructs theassignment controller 2017 to heighten the transmission rate of themodem circuit 2015. It is preferable in the operation that thetransmission rate of the modem 2016 is lowered in association with thevariable control of the transmission rate of the modem 2015.

The transmission rates of the radio modems 2015 and 2016 may also bevariably controlled by a communication technique using a plurality ofantennas such as the MIMO scheme.

Referring next to FIG. 8 , description will be given of other examplesof the transmission rate assignment controller and the radio modem. FIG.8 shows only part of the system associated with the transmission rateassignment control. In FIG. 8 , the same functional constituentcomponents as those of FIG. 1 are assigned with the same referencenumerals.

In FIG. 8 , a transmission rate assignment controller 9005 operates in asimilar way as the transmission rate assignment controller 1001described above and assigns transmission rates respectively to radiomodems 9010 to 9013 according to an instruction from the controller2013. The modem circuits 9010 to 9013 are modems having respective fixedtransmission capacity values and differ from each other only in thefrequency band for transmission. The modems 9010 to 9013 respectivelyhave bands A to D as shown in FIG. 11 . Terminals 9006 and 9007 areinput terminals to receive signals and are arranged respectively forradio modems 9010 to 9013. In operation, the modems 9010 to 9013 may beappropriately combined with each other. For example, under supervisionof the assignment controller 9005, the modems 9010 and 9011 are employedto transmit video information and the modems 9012 and 9013 are utilizedfor communication with the network such as the Internet depending oncases. That is, while the interface circuit 2011 transmits by radiovideo information and audio information via the modems 9010 and 9011 tothe video display apparatus 200, the interface circuit 2012 communicatesvia the modems 9012 and 9013 with the network. In a situation wherein awide band is required to receive video information of high picturequality (e.g., video information of HD resolution) from the videoprocessing apparatus 100, the modems 9010 to 9012 are allocated totransmit video information and only the modem 9013 is allocated tocommunicate with the network such as the Internet. That is, theinterface circuit 2011 transmits video and audio information by radiovia the modems 9010 to 9012 to the video display apparatus 200, and theinterface circuit 2012 communicates with the network via the modem 9013.Resultantly, video information of high picture quality can becontinuously transmitted and it is also possible to communicate with theInternet. In particular, the broadcast signal is required to bepresented by synchronizing the time information sent from thebroadcasting station with that on the receiver side. According to theembodiment, the time information can be appropriately controlled withoutdeteriorating the quality of the video information.

Description will now be given supplementally of the High DefinitionDigital Multimedia Interface (HDMI). FIG. 7 shows an example the HDMIconfiguration mainly including a transmission side and a reception side.The transmission side includes a transmitter section 1601 and atransmission controller section 1603 to control the transmitter section1601. The transmitter section 1601 encodes a video signal (Y, Pb, Pr)and an audio signal to output resultant signals to a receiver section1604. Also, the transmitter section 1601 includes a TMDS encoder circuit1602 which converts the video signal (Y, Pb, Pr) and the audio signalrespectively into serial video data and serial audio data. On the otherhand, the reception side includes a receiver section 1604 and areception controller section 1606 to control the receiver section 1604.The receiver section 1604 receives the video data and the audio datafrom the transmitter section 1601 and conducts a TMDS decoding operationfor the data by a TMDS decoder circuit 1605 to thereby reproducebaseband video data and baseband audio data. A CEC line 1607 is anapparatus control line to transmit a control signal for apparatuses.Display specification information known as “DDC” is transmitted via aDDC line 1608. The reception side transmits to the transmission side aHot Plug Detect (HPD) signal 1609 indicating that a connection isestablished between apparatuses of the transmission and reception sides.

To conduct transmission according to the HDMI standard, apparatusesmutually recognize in a procedure as follows. A physical address isobtained via the DDC line. The physical address is an identificationnumber to discriminate an associated apparatus. By use of a CEC bus forbidirectional connection, a logical address is obtained forbidirectional communication of each apparatus. The logical address isidentification information defining a category of each apparatus, e.g.,a display or a recording apparatus.

FIG. 5 is a diagram to supplementally explain a radio interface 11between the video processing apparatus 100 and the video displayapparatus 200. In FIG. 5 , the apparatuses 100 and 200 are almost thesame as those described in conjunction with, for example, FIG. 1 . Tosimplify explanation, for the constituent components of the apparatus100, only the radio interface circuit 133 is shown in FIG. 8 and theother constituent components are not shown. For the constituentcomponents of the display apparatus 200, only the radio input/outputinterface circuit 2012 is shown and the other constituent components arenot shown. The interface circuits 133 and 2012 are bidirectionalinterfaces.

In FIG. 5 , a channel between antennas 81 and 84 and a channel betweenantennas 82 and 85 are channels to bidirectionally transmit a videosignal, an audio signal, and control signals indicating copyrightprotection and a replication restriction condition of contents. On theother hand, a channel between antennas 83 and 86 is disposed to transmitan inter-apparatus control signal. Bit selection circuits 811 and 812receive the video signal, the audio signal, the control signalsindicating copyright protection and a replication restriction conditionof contents, and the inter-apparatus control signal. In thedemodulation, the QPSK demodulation scheme is more resistive againsttransmission errors as compared with the 64QAM demodulation scheme. Forthe transmission efficiency, the 64QAM demodulation scheme is superiorto the QPSK demodulation scheme. Description will now be given of asituation wherein a video signal, an audio signal, and control signalsindicating copyright protection and a replication restriction conditionof contents are fed from the video processing apparatus 100 to the videodisplay apparatus 200. Assume in the operation that the transmissiondirection from the apparatus 100 to the apparatus 200 is an uplinkdirection and the transmission direction from the apparatus 200 to theapparatus 100 is an downlink direction.

To transmit information, the video processing apparatus 100 determines,by a carrier detector circuit, not shown, a state of an associatedtransmission path, i.e., whether or not the channel is reserved foranother apparatus. In the carrier detection, a check is made todetermine whether or not a carrier is detected in a predeterminedfrequency band for a predetermined period of time. If it is detected bythe detector that the channel is occupied by another apparatus, thecheck is again carried out after a lapse of a predetermined period oftime to determine whether or not an available channel is present. Ifsuch available channel is present, the condition is notified to themicroprocessor 115 of the video processing apparatus 100. Themicroprocessor 115 outputs from a QPSK modem circuit 803 a channel userequest signal as an inter-apparatus control signal to secure thechannel use right. Thereafter, the microprocessor 115 sends atransmission request signal to a bit selection circuit 811. An errorcontrol circuit 843 adds an error control bit for error detection andcorrection to the transmission request signal and then transfers thesignal to the QPSK modem 803. The modem 803 conducts a QPSK modulationfor the signal to resultantly transmit a radio signal via the antenna 83to the display apparatus 200. The apparatus 200 then receives the radiosignal by the antenna 86, carries out a QPSK demodulation for the signalby a QPSK modem 806, conducts error detection and correction control forthe demodulated signal by an error control circuit 847 to produce aninter-apparatus control signal, and delivers the signal to the bitselection circuit 812.

The microprocessor in the video display apparatus 200 decodes theinter-apparatus control signal and receives the transmission requestsignal from the video processing apparatus 100 together with apparatuscategory information regarding the apparatus 100 (information toidentify a category indicating whether the associated apparatus is adisplay apparatus or a recording apparatus) and an apparatusidentification number of the apparatus 100. An image to urge the user todetermine whether or not a connection is established to the videoprocessing apparatus 100 is presented on a display screen of the displayapparatus 200. In response thereto, the user indicates allowance for theconnection by using an input device such as a remote controller of thedisplay apparatus 200. Thereafter, between the apparatuses 100 and 200,the apparatus category information and the identification number toidentify each of the apparatuses are communicated to exchangeinformation to observe the copyright protection and the replicationrestriction condition of the content. If there does not exist anyproblem, it is allowed that the apparatuses 100 and 200 are connected toeach other. In a situation wherein the connection is meaningless, forexample, each of the apparatuses 100 and 200 is an input or outputdedicated unit or the copyright protection or the replicationrestriction condition of the content is not observed, the connectingoperation is interrupted and an indication of the condition is displayedon the apparatuses 100 and 200. Description will now be given of asituation wherein the copyright protection and the replicationrestriction condition of the content are observed.

By using the video signal, the audio signal, and the control signalindicating the copyright protection and the replication restrictioncondition of the contents associated with the video and audio signalswhich are inputted to an interface circuit 172, two bits are selectedfrom the Most-Significant Byte (MSB) of the video signal so that errordetection and correction control bits are added thereto by an errorcontrol circuit 841 and the resultant signal is fed to a QPSK modemcircuit 801. The modem circuit 801 conducts a QPSK modulation for thesignal and then transmits an associated radio signal from the antenna81. To the remaining third to eighth bits, an error control circuit 842adds error detection and correction control bits to send the resultantsignal to a 64QAM modem circuit 802. The modem 802 carries out a 64QAMmodulation for the signal and resultantly transmits a radio signal fromthe antenna 82.

In the video display apparatus 200, a QPSK modem circuit 804 conducts aQPSK demodulation for the signal received via the antenna 84 and anerror control circuit 845 carries out error control for the resultantsignal to output two high-order bits of the video signal to the bitcontrol circuit 812. For the remaining signals received via the antenna85, a 64QAM modem circuit 805 conducts a 64QAM demodulation. For theresultant signal, an error control circuit 846 carries out error controlto output the obtained signal to the bit control circuit 812.

Description will now be given of the inter-apparatus control signal.When an inter-apparatus control signal is sent in a downlink direction,i.e., from the video display apparatus 200 to the video processingapparatus 100, the signal is fed from the bit selection circuit 812 viathe error control circuit 847 to the QPSK modem circuit 806 to bedemodulated. The demodulated signal is delivered from the antenna 86.The video processing apparatus 100 receives the signal by the antenna 83to send the signal to the QPSK modem circuit 803. For the signal, thecircuit 803 conducts a QPSK demodulation. For the demodulated signal, anerror detection and correction is carried out by the error controlcircuit 843 to feed the resultant signal to the bit selection circuit811. Conversely, when an inter-apparatus control signal is transmittedin an uplink direction, i.e., from the video processing apparatus 100 tothe video display apparatus 200, the signal is fed from the bitselection circuit 811 via the error control circuit 843 to the QPSKmodem circuit 803 to be modulated. The modulated signal is outputtedfrom the antenna 83. The display apparatus 200 receives the signal bythe antenna 86. For the signal, the modem 806 conducts a QPSKdemodulation. For the demodulated signal, the error control circuit 847conducts an error detection and correction to send the resultant signalto the bit selection circuit 812. By virtue of the operation, there isobtained an advantage that for the inter-apparatus control signal whichis important to construct the system, an erroneous operation is lessfrequently occurs even in a noisy environment.

In the configuration of the embodiment, for two high-order bits of thedigital signal, there can be conducted the transmission highly resistiveagainst noise with a relatively low transmission rate. That is, by usingthe fact that higher order bits of a video signal more strongly affectthe picture quality, two bits are taken out from the video signal inorder of MSB and a transmission path using the QPSK modulation isallocated to the information of these two bits, to thereby preventingdeterioration of the picture quality. In a system in which the audioinformation is more important than the video information, thetransmission path using the QPSK modulation may be allocated toimportant bits, e.g., two high-order bits of the audio signal.

When a human perceives an image on a screen, a higher-frequency is lessinfluential as compared with a lower-frequency component for thefrequency component in the horizontal direction of the screen and thatin the vertical direction thereof. For a moving object on the screen, itis likely that the human eyes cannot appropriately follow a high-speedmovement of the object. By using these tendencies, it is also possiblethat in the horizontal direction of the screen, the signal is subdividedinto a lower-frequency component and a higher-frequency component sothat the QPSK modulation is used for the lower-frequency component andthe 64QAM modulation is employed for the higher-frequency component. Asa result, within the limited transmission bands, the noise resistivitycan be increased for important information and the overall transmissioncapacity is secured. Similarly, it is possible that in the verticaldirection of the screen, the signal is subdivided into a lower-frequencycomponent and a higher-frequency component so that the QPSK modulationis used for the lower-frequency component and the 64QAM modulation isemployed for the higher-frequency component. Resultantly, within thelimited transmission bands, it is possible to heighten the noiseresistivity for important information and the overall transmissioncapacity is secured. Additionally, by combining the operation for thefrequency component in the horizontal direction of the screen with thatfor the frequency component in the vertical direction of the screen, thenoise resistivity can be strengthened for desired important information.

In the description above, the error control circuits 841 to 843 add theerror control information items to the bits inputted respectivelythereto. However, it is also possible that the bits inputted to thecircuits 841 to 843 are collectively treated as one word to add errorcontrol information to the word. This advantageously leads to asimplified configuration of the error control circuits.

Although detailed description has not been given of the encryption inthe embodiment shown in FIG. 5 , it is possible to execute theprocessing as shown in FIG. 6 by combining the encryption circuit 171with the interface circuit 172. FIG. 6 shows an example of theconfiguration to carry out the encryption in the system of FIG. 5 . Thesystem shown in FIG. 6 includes encryption/decryption circuits 821 to826, interface circuits 830 and 831 including encryption, and errorcontrol circuits 841 to 847.

In the example of FIG. 6 , the bit selection circuit 811 selectspredetermined bits as in the example shown in FIG. 5 . For therespective bits, the error control circuits 841 and 842 conduct errorcontrol. For the resultant signals, the encryption/decryption circuits821 and 822 respectively carry out encryption. The obtained signals areinputted respectively to the QPSK modem circuit 801 and the 64QAM modemcircuit 802 to be demodulated. The signals demodulated respectively bythe circuits 801 and 802 are delivered to the encryption/decryptioncircuits 824 and 825 to be decrypted. The decrypted signals are fed tothe bit selection circuit 812 and are therein bit-combined with eachother. As a result, the signal processing can be executed according toimportance of signals to possibly suppress errors in the processing ofmore important information. Hence, the signals of information can beefficiently transmitted without deteriorating the picture quality.

It is also possible to further increase transmission efficiency bycombining lossless coding with the encryption/decryption circuits 821 to826. For example, in the example of FIG. 6 , before executing theencryption processing in the encryption/decryption circuits 821 to 823,the number of bits to be transmitted is reduced, for example, by use ofreversible arithmetic codes based on a statistic property. In the videodisplay apparatus 200, the received signals are decrypted by theencryption/decryption circuits 824 to 826. Thereafter, the reversiblecodes corresponding to the circuits 821 to 823 are decoded to be fed tothe error control circuits 845 to 846 for the error detection andcorrection thereof. The obtained signals are fed to the bit selectioncircuit 812 to be bit-combined with each other. Since the transmissionrate of the information to be transmitted can be lowered by combiningthe reversible codes as above, the signal can be more efficientlytransmitted.

Description will be supplementally given of the encryption. By usingAES128 bit encryption in all encryption circuits for the encryption, itis possible to conduct the encryption with high safety for theprotection of contents. Moreover, if the AES128 bit encryption isemployed for the content encryption circuit 821 and the Data EncryptionStandard (DES) encryption is used for the other encryption circuits,there can be easily constructed a system in which the protection ofimportant contents and the processing efficiency are appropriatelyachieved.

It is also possible to construct a system in which a changeoveroperation is conducted between the baseband signal transmission and thecompressed signal transmission in response to an inter-apparatus controlsignal. With the configuration, to transmit a compressed signalaccording to, for example, a content protection request, the errorresistivity is enhanced on the transmission path by transmitting thesignal using the QPSK modulation. To transmit the baseband signal, thetransmission efficiency is increased by using the 64QAM modulation.

The operations of the video processing apparatus 100 and the videodisplay apparatus 200 in FIG. 6 are basically similar to those of theapparatuses 100 and 200 shown in FIG. 5 . To transmit a signal, thevideo processing apparatus 100 determines the state of an associatedtransmission path, specifically, detects by a carrier detection circuit,not shown, whether or not the channel to be used is occupied by anotherapparatus. In the carrier detection, a check is made to determinedwhether or not a carrier is detected in a predetermined frequency bandfor a predetermined period of time. If it is detected by the detectorthat the channel is occupied by another apparatus, the check is againcarried out after a lapse of a predetermined period of time to determinewhether or not an available channel is present. If such availablechannel is present, the condition is notified to the microprocessor 115of the video processing apparatus 100. The microprocessor 115 outputsfrom the QPSK modem circuit 803 a channel use request signal as aninter-apparatus control signal to secure the channel use right.Thereafter, the microprocessor 115 sends a transmission request signalto a bit selection circuit 811.

The error control circuit 843 adds error control bits for errordetection and correction to the transmission request signal which is inturn encrypted by an encryption/decryption circuit 823 and thentransferred to the QPSK modem 803. The modem 803 conducts a QPSKmodulation for the signal to resultantly transmit a radio signal via theantenna 83 to the display apparatus 200. The apparatus 200 then receivesthe radio signal by the antenna 86, carries out a QPSK demodulation forthe signal by the modem 806, and decrypts the signal by theencryption/decryption circuit 826. For the demodulated signal, the errorcontrol circuit 847 conducts error detection and correction control toproduce an inter-apparatus control signal and delivers the signal to thebit selection circuit 812. The microprocessor in the video displayapparatus 200 decodes the inter-apparatus control signal and receivesthe transmission request signal from the video processing apparatus 100together with apparatus category information regarding the apparatus 100(information to identify a category indicating whether the associatedapparatus is a display apparatus or a recording apparatus) and anapparatus identification number of the apparatus 100. An image to urgethe user to determine whether or not a connection is established to thevideo processing apparatus 100 is presented on a display screen of thedisplay apparatus 200. In response thereto, the user indicates allowancefor the connection by use of an input device such as a remote control ofthe display apparatus 200. Thereafter, between the apparatuses 100 and200, the apparatus category information and the identification number toidentify each of the apparatuses are communicated to exchangeinformation to observe the copyright protection and the replicationrestriction condition of the content. If there does not exist anyproblem, it is allowed that the apparatuses 100 and 200 are connected toeach other. In a situation wherein the connection is meaningless, forexample, each of the apparatuses 100 and 200 is an input or outputdedicated unit or the copyright protection or the replicationrestriction condition of the content is not observed, the connectingoperation is interrupted and the status is displayed on the apparatuses100 and 200. As above, in a situation wherein the copyright protectionand the replication restriction condition of the content are observed,the connection is established to transmit video and audio signals fromthe video processing apparatus 100 to the video display apparatus 200.

Second Embodiment

FIG. 3 shows a second embodiment of the present invention and is anotherconfiguration of the video display apparatus 200 shown in FIG. 1 . Theconfiguration of FIG. 3 is partially equal to that of FIG. 2 . The sameconstituent components are assigned with the same reference numerals,and detailed description thereof will be avoided. The apparatus 200 ofFIG. 3 includes a decryption circuit 212, encryption/decryption circuits245 and 290, compression/transcoding circuits 291 and 292, and copycontrol circuit 293 which is a multiplexing circuit.

In the embodiment of FIG. 3 , when a baseband signal is inputted via theterminal 201 or 202, the system operates in almost the same way as forthe embodiment shown in FIG. 2 . Each of the compression/transcodingcircuits 291 and 292 operates as a compression circuit for the basebandsignal. When a compressed signal is inputted from the terminal 201 or202, the signal is fed via the input/output interface 210 to theencryption/decryption circuit 212 to be decrypted. The signal is thendelivered to the demultiplexer circuit 250 to be separated into acompressed video signal and a compressed audio signal. These signals areinputted to the replication control circuit 290, which determinesallowance or rejection of replication of the signals based oninformation indicating a replication restriction condition. If thereplication is allowed, the bit rates of the compressed video and audiosignals are lowered by the compression/transcoding circuits 291 and 292by using, for example, a compression method having high compressionefficiency according to necessity. Output signals from the circuits 291and 292 are multiplexed by the multiplexer circuit 293 to be inputted tothe encryption/decryption circuit 245. In this situation, if thereplication is allowed by the replication control circuit 290, thecircuit 245 encrypts the input signal for the storage thereof to storethe encrypted signals in the storage 230 and/or the memory 221. Toreproduce the stored signal, the circuit 245 decrypts the signal readfrom the storage 230 or the memory 221, and the decrypted signal isseparated by the demultiplexer circuit 241 into a video signal and anaudio signal. Thereafter, these signals are processed in almost the sameway as described above and the user resultantly enjoys the image and thesound. In a situation wherein the user enjoys the image and the soundwhile storing the signal in the storage 230 or the memory 221, thesignal from the multiplexer 293 is delivered via theencryption/decryption circuit 245 to the demultiplexer 241 to beprocessed almost in the same way as above. In this case, it is possibleto confirm the picture quality of the transcoded signal. To enjoy theimage and the sound without storing the signal, the signal is fed fromthe decryption circuit 212 via the circuit 245 to the demultiplexer 241to be separated into a video signal and an audio signal. Thereafter, thesignals are processed in substantially the same way as described above.

According to the embodiment of FIG. 3 , also in a situation wherein acompressed signal is inputted thereto, by conducting the transcoding forthe signal, the signal can be efficiently stored with a high compressionratio. Although the signal processing is carried out by use of circuitssuch as the compression circuits 111 and 113 in the embodiment, thecircuits may be implemented by software means. In this situation, therecan also be obtained similar advantages. According to the presentinvention, the signal processing may be accomplished in any appropriatefashion, that is, the present invention does not particularly limit howto implement the signal processing.

It should be further understood by those skilled in the art thatalthough the foregoing description has been made on embodiments of theinvention, the invention is not limited thereto and various changes andmodifications may be made without departing from the spirit of theinvention and the scope of the appended claims.

1. A display apparatus, comprising: memory having an operating system stored thereon; a processor; an HDMI (High Definition Multimedia Interface) interface; an audio output; a display screen capable of displaying information; and a radio modem, wherein the processor controls the radio modem to execute a first wireless communication with the Internet or a local area network on a first carrier frequency, and to receive a first stream of video data and audio data from the Internet or the local area network, wherein the display screen displays video based on the received first stream of video data and the audio output outputs sound based on the received first stream of audio data when the first wireless communication is executed, wherein the processor controls the radio modem to execute a second wireless communication with a cellular phone on a second carrier frequency which is different from the first carrier frequency, and to receive a second stream of video data and audio data from the cellular phone, wherein the display screen displays video based on the received second stream of video data and the audio output outputs sound based on the received second stream of audio data when the second wireless communication is executed, and wherein the processor controls the radio modem to execute the second wireless communication based on a user instruction from the cellular phone.
 2. The display apparatus of claim 1, wherein the display screen further displays information image used to connect with the cellular phone, and the second wireless communication is executed by a user operation via the displayed information image.
 3. The display apparatus of claim 1, wherein upon receiving a user instruction from the cellular phone during the execution of the first wireless communication, the processor controls the radio modem to execute the second wireless communication simultaneously with the first wireless communication.
 4. The display apparatus of claim 3, the display screen is capable of displaying video based on the received first stream of video data and the video based on the received second stream of video data simultaneously.
 5. The display apparatus of claim 1, wherein the display apparatus is further capable of receiving a user instruction from a remote controller, and the processor controls the first wireless communication or the second wireless communication via the radio modem based on the user instruction from the remote controller.
 6. The display apparatus of claim 5, wherein the remote controller is a remote controller for the display apparatus.
 7. The display apparatus of claim 1, wherein the radio modem is configured to select the first carrier frequency among a plurality of predetermined carrier frequencies when executing the first wireless communication and select the second carrier frequency among the plurality of predetermined carrier frequencies when executing the second wireless communication.
 8. The display apparatus of claim 1, wherein the HDMI interface is configured to connect an external device and to receive a third stream of video data and audio data from the connected external device, wherein the display screen displays video based on the received third stream of video data and the audio output outputs sound based on the received third stream of audio data.
 9. The display apparatus of claim 8, wherein the first stream and the second stream are at least part of a compressed signal, and the third stream is at least part of an uncompressed signal.
 10. The display apparatus of claim 8, wherein the display screen displays one or more of video based on the received first stream of video data, video based on the received second stream of video data and video based on the received third stream of video data.
 11. The display apparatus of claim 1, wherein the display apparatus is configured to receive a digital broadcast signal.
 12. The display apparatus of claim 1, wherein the radio modem is configured to execute the first wireless communication using QAM or QPSK modulation/demodulation.
 13. The display apparatus of claim 12, wherein the radio modem is configured to execute the second wireless communication using QAM or QPSK modulation/demodulation.
 14. A display apparatus, comprising: memory having an operating system stored thereon; a wireless communication resource allocation controller; an HDMI (High Definition Multimedia Interface) interface; an audio output; a display screen capable of displaying information; and a radio modem, wherein the wireless communication resource allocation controller controls the radio modem to allocate wireless communication resources to a first wireless communication using a first carrier frequency, when communicating with the Internet or a local area network, wherein when the first wireless communication is executed, the radio modem receives a first stream of video data and audio data from the Internet or the local area network, the display screen displays video based on the received first stream of video data, and the audio output outputs sound based on the received first stream of audio data, wherein the wireless communication resource allocation controller controls the radio modem to allocate wireless communication resources to a second wireless communication using a second carrier frequency which is different from the first carrier frequency, when communicating with a cellular phone, wherein when the second wireless communication is executed, the radio modem receives a second stream of video data and audio data from the cellular phone, the display screen displays video based on the received second stream of video data, and the audio output outputs sound based on the received second stream of audio data, and wherein the wireless communication resource allocation controller controls the radio modem to execute the second wireless communication based on a user instruction from the cellular phone.
 15. The display apparatus of claim 14, wherein the display screen further displays information image used to connect with the cellular phone, and the second wireless communication is executed by a user operation via the displayed information image.
 16. The display apparatus of claim 14, wherein upon receiving a user instruction from the cellular phone during the execution of the first wireless communication, the wireless communication resource allocation controller controls the radio modem to execute the second wireless communication simultaneously with the first wireless communication.
 17. The display apparatus of claim 14, the display screen is capable of displaying video based on the received first stream of video data and the video based on the received second stream of video data simultaneously.
 18. The display apparatus of claim 14, wherein the display apparatus is further capable of receiving a user instruction from a remote controller, and the wireless communication resource allocation controller controls the first wireless communication or the second wireless communication via the radio modem based on the user instruction from the remote controller.
 19. The display apparatus of claim 18, wherein the remote controller is a remote controller for the display apparatus.
 20. The display apparatus of claim 14, wherein the wireless communication resource is a frequency band or a transmission capacity. 